infra container: replace pause with catatonit

Podman has been using catatonit for a number of years already. Thanks to @giuseppe, catatonit is now able to run as a pause process which allows us to replace the pause binary entirely. Signed-off-by: Valentin Rothberg <[email protected]>
mscherer · Nov 15, 2021 · 5934e4c · 5934e4c
1 parent 58cf0d4
commit 5934e4c
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Showing 4 changed files with 10 additions and 12 deletions.
diff --git a/contrib/spec/podman.spec.in b/contrib/spec/podman.spec.in
@@ -58,6 +58,7 @@ BuildRequires: libselinux-devel
 BuildRequires: pkgconfig
 BuildRequires: make
 BuildRequires: systemd-devel
+Requires: catatonit >= 0.1.7
 Requires: containers-common
 Requires: conmon
 Requires: containernetworking-plugins >= 0.6.0-3

diff --git a/pkg/specgen/generate/pod_create.go b/pkg/specgen/generate/pod_create.go
@@ -29,19 +29,16 @@ func buildPauseImage(rt *libpod.Runtime, rtConfig *config.Config) (string, error
 		return imageName, nil
 	}
 
-	// NOTE: Having the pause binary in its own directory keeps the door
-	// open for replacing the image building with using an overlay root FS.
-	// The latter turned out to be complex and error prone (see #11956) but
-	// we may be able to come up with a proper solution at a later point in
-	// time.
-	pausePath, err := rtConfig.FindHelperBinary("pause/pause", false)
+	// Also look into the path as some distributions install catatonit in
+	// /usr/bin.
+	catatonitPath, err := rtConfig.FindHelperBinary("catatonit", true)
 	if err != nil {
 		return "", fmt.Errorf("finding pause binary: %w", err)
 	}
 
 	buildContent := fmt.Sprintf(`FROM scratch
-COPY %s /pause
-ENTRYPOINT ["/pause"]`, pausePath)
+COPY %s /catatonit
+ENTRYPOINT ["/catatonit", "-P"]`, catatonitPath)
 
 	tmpF, err := ioutil.TempFile("", "pause.containerfile")
 	if err != nil {

diff --git a/test/apiv2/40-pods.at b/test/apiv2/40-pods.at
@@ -110,11 +110,11 @@ t GET libpod/pods/fakename/top 404 \
   .cause="no such pod"
 
 t GET libpod/pods/foo/top 200 \
-  .Processes[0][-1]="/pause" \
+  .Processes[0][-1]="/catatonit -P" \
   .Titles[-1]="COMMAND"
 
 t GET libpod/pods/foo/top?ps_args=args,pid 200 \
-  .Processes[0][0]="/pause" \
+  .Processes[0][0]="/catatonit -P" \
   .Processes[0][1]="1" \
   .Titles[0]="COMMAND" \
   .Titles[1]="PID" \

diff --git a/test/e2e/pod_create_test.go b/test/e2e/pod_create_test.go
@@ -369,13 +369,13 @@ var _ = Describe("Podman pod create", func() {
 		check1 := podmanTest.Podman([]string{"container", "inspect", "--format", "{{.Config.Entrypoint}}", data.Containers[0].ID})
 		check1.WaitWithDefaultTimeout()
 		Expect(check1).Should(Exit(0))
-		Expect(check1.OutputToString()).To(Equal("/pause"))
+		Expect(check1.OutputToString()).To(Equal("/catatonit -P"))
 
 		// check the Path and Args
 		check2 := podmanTest.Podman([]string{"container", "inspect", "--format", "{{.Path}}:{{.Args}}", data.Containers[0].ID})
 		check2.WaitWithDefaultTimeout()
 		Expect(check2).Should(Exit(0))
-		Expect(check2.OutputToString()).To(Equal("/pause:[/pause]"))
+		Expect(check2.OutputToString()).To(Equal("/catatonit:[-P]"))
 	})
 
 	It("podman create pod with --infra-command", func() {